有机配位剂对重金属絮凝剂DTSPAM去除水中Cd2+性能的影响

以聚丙烯酰胺、甲醛、亚硫酸氢钠、二硫化碳、氢氧化钠为原料，制备出新型重金属絮凝剂二硫代羧基化磺甲基聚丙烯酰胺（DTSPAM），考察了3种常见有机配位剂EDTA、焦磷酸钠、柠檬酸钠对DTSPAM除Cd²⁺性能的影响.实验结果表明，在单一含Cd²⁺水样中，pH值为3.0~6.0时DTSPAM对Cd²⁺均有较好的去除性能；在不同EDTA浓度、不同pH值下的混合水样中，EDTA对DTSPAM除Cd²⁺均呈抑制作用；水样pH值为5.0、6.0时，焦磷酸钠、柠檬酸钠对DTSPAM除Cd²⁺均表现出促进作用，而pH值为2.0~4.0时，焦磷酸钠、柠檬酸钠对DTSPAM除Cd²⁺均呈抑制作用.

Effect of organic coordination agents on the removal of Cd2+ with heavy metal flocculant DTSPAM

Polyacrylamide, formaldehyde, sodium hydrogen sulfite, carbon disulfide and sodium hydroxide were used as raw materials to prepare a novel heavy metal flocculant, named dithiocarboxyl sulfomethy-polyacrylamide (DTSPAM). The effects of three common organic coordination agents, such as EDTA, sodium pyrophosphate and sodium citrate on the removal of Cd²⁺ by DTSPAM were studied. The experimental results showed that DTSPAM could remove Cd²⁺ effectively in water without organic coordination agents at pH from 3.0 to 6.0. EDTA would inhibit the removal of Cd²⁺ by DTSPAM in the mixed water samples with different concentrations of EDTA and different pH. However, sodium pyrophosphate and sodium citrate could promote the removal of Cd²⁺ by DTSPAM at 5.0 or 6.0, and the existence of sodium pyrophosphate and sodium citrate would inhibit the removal of Cd²⁺ by DTSPAM at pH from 2.0 to 4.0.